"It's very important we protect all businesses across Australia from the impact of lower business tax rates in other parts of the world," Senator Cormann told AM.

"Of course at every election we consider carefully what the people have told us … but when it comes to the central components of our plan for a stronger economy and more jobs, we remain absolutely and totally focused."

While Labor leader Bill Shorten opposes the next round of tax cuts for big businesses, he has also declared that if the Prime Minister scraps the plan then he should resign.

"If Mr Turnbull drops his corporate tax cuts for the big end of town, then he should go with them," he said.

"I thought they were always a silly idea, he has made it his signature economic policy.

"If he hasn't even got the intestinal fortitude to support his own economic values, what he really believes, then he shouldn't hang around either."

Mr Shorten attributed some of Labor's success at the by-elections to the Coalition's policy.

"The reason why we could offer promises in health care, in school funding and looking after people's jobs is because we're not giving tens of billions of dollars away to big banks and big corporations," he said.